Fire hits Mercedes testing

Lewis Hamilton will be hoping to avoid the gremlins that forced Nico Rosberg and Mercedes to abandon day one of testing after just 14 laps.

Rosberg set the early pace at the Circuito de Jerez before the W04, the new car that was unveiled on Monday, suffered a short burst of flames that forced him off track.

Mercedes engineers discovered an electrical fault sparked by a faulty wiring loom was the cause, leaving Rosberg a frustrated figure on the sidelines.

Via their Twitter feed, Mercedes said: "After identifying the cause of the problem we will not be running again today whilst parts are modified ready for tomorrow.

"The part which requires modification is the wiring loom where the electrical fault originated this morning."

After signing a three-year contract with Mercedes, who have won just one race in three seasons on their return to F1, Hamilton will get behind the wheel of the car for the first time on Wednesday.

Despite the issues and the lack of running, Rosberg is confident the car is an improvement on the one he drove last year which gave him a win in China before a long, slow decline over the rest of the season.

"I can guarantee you it will be a big step forward, but of course everybody else is also moving forward and we're hoping that we've closed the gap," said Rosberg.

"Last year, at the end of the season, it was nearly more than a second. We have to get closer, and we will.

"They have given us a good base now, and it's up to us make the most of it here, find all the problems as we've done today, and improve it.

"We need to feed back to the factory the main things that are still holding us back, the main things they need to keep working on.

"That's what it's about, but it's going in the right direction. I feel very good, very positive.

"I can't say if the car was quick or not, but feeling-wise I was very comfortable, I could push, the balance was okay, and it was very enjoyable to drive."

Rosberg insists there will be a constant push over the course of the season, resisting the temptation to look ahead to next year when new engine regulations come into force.

"Definitely not, we're fully concentrated on 2013 because we, as Mercedes, need to make it happen this year, so it's full speed ahead," said Rosberg.

"Any improvement also has to be more consistent throughout the year, not like last year when we started okay but completely fell off.

"Improvement means a very okay car through the whole season with a win or two maybe, moving forward and thinking we are on the right track to become the best."